Technical Field
The present invention relates to a heating apparatus used, for example, for image forming apparatuses, such as printers and copiers, and a heating rotating member used for the heating apparatus.
Description of the Related Art
As a heating apparatus used for conventional image forming apparatuses, such as printers and copiers, for example, the heating apparatus described in Japanese Patent Application Laid-open No. 2013-97315 is known.
This heating apparatus has a heating rotating member, a power feeding member for feeding power to the heating rotating member, and a pressurizing member that comes into pressure contact with the heating rotating member to form a nip portion. By feeding power to the heating rotating member to generate Joule heat, the heating apparatus allows high-speed start-up and saves energy. The heating rotating member has a heat generating layer coated with an insulating layer. The heating rotating member generates heat by feeding power directly to the heat generating layer, enabling a reduction in warm-up time.
Technical Problem
In the conventional heating rotating member, however, the insulating layer may be damaged by being rubbed by foreign matter entering the image forming apparatus or by recording materials, and the damage may even reach the heat generating layer. Moreover, for example, in connection with a jam eliminating process forcibly executed by a user, the heat generating layer may be damaged by a cutter. The heat generating layer damaged in this manner may locally increase a current density around ends of the damaged portion of the heat generating layer, leading to abnormal heat generation in the corresponding portions.